MAJOR EARTH RESOURCES CH 3.1

PAGE 68

NATURAL RESOURCES PAGE 68

Natural Resources - A resource is anything supplied by the Earth to satisfy a particular need of human beings or other living things.

Natural resources found on the Earth include:

• Rocks, minerals, fossils, soil, air, water, living things and sunlight.

Renewable and non-renewable resources

• Renewable resources can be replaced in less than a human life span eg trees, water

• Non-renewable resources may take millions of years to be replaced eg coal, oil

LIVING THINGS AS A RESOURCE PAGE 69

Living things can be a resource for humans and other organisms egs:

• Tapeworms in the gut of other animals

• Plants convert waste carbon dioxide into oxygen

• Some plants need animals to pollinate them

• Humans use plants and animals for food, shelter, clothing, medicines, fuel

• Generally living things are a renewable resource, as all living things reproduce and replace themselves – forests, herds, fish and crops.

AIR AS A RESOURCE PAGE 70

Air contains

• Nitrogen 78% - plants need to make proteins

• Oxygen 21 % - essential to release energy from food

• CO2 0.03% - plants use with sunlight to make their own food – during photosynthesis

• Other Gases 0.97% - Ozone shield the earth form ultraviolet light and water vapour is part of the water

cycle.

Nitrogen, Oxygen and Carbon are all re-cycled and are therefore renewable resources.

PHOTOSYNTHESIS (OXYGEN CYCLE)

CARBON CYCLE

IN THE FOLLOWING SLIDES ONLY COPY THE YELLOW SECTIONS.

SUNLIGHT AS A RESOURCE PAGE 71

Sunlight is an essential resource because:

• Plants use sunlight to produce food

• It keeps the planet warm enough to prevent freezing

Sunlight will be available for millions of years, therefore is considered a renewable resource.

WATER AS A RESOURCE PAGE 71Life on Earth is based on the availability of water – it is therefore considered extremely important.

Water is a renewable resource because it can move from place to place and replenish an area – it has a cycle.

Water can be formed when

• Trees burn

• The combustion of fossil fuels like oil and coal

• Living things release energy in their bodies

• The total amount of water on the planet has been relatively constant.

ROCKS AS A RESOURCE PAGE 72Rocks provide 2 different resources – the rocks themselves and the minerals in rocks.

Hard rocks – (usually volcanic) are used for heavy construction.

Soft rocks – (usually sedimentary) are used for walls, paving and statues.

Minerals have many uses including:

• Bauxite (Weipa) – aluminium for aircraft and canned goods

• Haematite - iron for steel in ships and cars

• Malachite – copper for electrical wiring

• Halite – sodium chloride for table salt and some medicines.

Rocks take millions of years to form, so both the rocks and the materials (coal, oil, minerals) they contain are considered to be non-renewable.

SOIL AS A RESOURCE PAGE 73

Rocks can be worn down by the processes of weathering and then carried away by erosion – this is a very long cycle.

Weathering is the process of breaking rocks down into smaller pieces by:

1. Changes in temperature – splits rocks

2. Water forming ice in these cracks – splits the rocks

3. Running water and waves

4. Strong winds blasting

5. Natural chemicals in the air, soil and water attack the rocks.

EROSION AND DEPOSITION PAGE 73Rocks are broken down into sediments by the weathering. Sediments can build up around the parent rock or be carried away by the agents of erosion (wind and water or ice) in the process of erosion.

These particles are carried away and then later dropped by the wind, water or ice in the process of deposition (in some cases sedimentation).

This can create new soil composed of:

• Fine rock particles

• Living organisms

• Humus – decaying wastes and organisms

• Water

• Dissolved minerals and gases

FERTILIZERS PAGE 75

Fertilizers provide mineral such as phosphorus and nitrogen nutrients to plants.

Common fertilizers include:

• Animal droppings such as manure

• Blood and bone from abattoirs

• Chemical fertilizers – super phosphate

Soil is a non-renewable resource as generally it is being removed rather than deposited – eg rain erosion, tornadoes, cyclones, ocean, fast running rivers.

RENEWABLE VS NON-RENEWABLE

Resource Renewable or non-renewable

Explanation. What about this resource makes it renewable or non-renewable?

Sunlight

Rocks

Oxygen

Living things

Water

Oil

Minerals

Yes

Yes

Yes

Yes

No

No

No

Renewable – more is available each new day

Renewable – Plants make more in photosynthesis

Renewable – Replaced by reproduction

Renewable – replaced in the water cycle

Non-renewable – most were formed millions of years ago

Non-renewable – formed millions of years ago

Non-renewable – the amount was set when the earth was formed

Renewable resources can be replaced in less than a human life spanNon-renewable resources may take millions of years to be replaced

REVIEW QUESTIONS PAGE 76

1, 5, 6, 7, 8, 12, 13, 15